Long-press for 'Shift' should respect the longpress timeout setting

[devycarol]

Is your feature request related to a problem? Please describe.
Did you know you can long-press shift to activate caps lock? I didn't discover this until I was scraping through the config files and saw that there's an attribute for "config_longpress_shift_lock_timeout". I've likely tried for that functionality in the past and just assumed it wasn't there, because it has a hard-coded value of 1200ms!

Describe the solution you'd like
The shift-lock long press should just use the same duration as all the other keys, as set in the advanced preferences.

Use case
I can certainly speak for myself that holding for 1.2 seconds is way too long to be remotely useful for activating caps lock.

Describe alternatives you've considered (if any)
Simply reduce that hard-coded value. I still think that would be counter-intuitive and that it'd be better to just respect the setting for the rest of the keys.

Another option: use the user-set duration, but also apply a multiplier like what is used for the space bar. I don't see any reason for this, because I don't think people are prone to accidentally linger a shift key tap longer than they would any other key.

I think these durations should be consistent across the board unless there's a good reason not to be—it's important to be respectful of muscle-memory.